Hamworthy F40V, Installation, Commissioning And Operating Instructions

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HAMWORTHY HEATING LTD
52
FLEET V series 500001213/G
vent pipe must rise continually, any valve fitted between a boiler and the open vent pipe for maintenance
purposes shall be of the 3 way type such that when closed to the vent pipe the boiler will be open to atmosphere.
The vent pipe shall be protected against freezing where this might occur. See BS 6644 for detailed information on
Open Vent and Cold Feed Pipes.
E1.5 Thermometer
A thermometer complete with pocket should be fitted in the pipe work to indicate water flow temperature. See
Figure E1.1.1 for typical position.
E1.6 Drain Valves
Each boiler has a 15mm NB drain valve fitted in the boiler return, for draining the boiler only. The heating system
in total should have drain valves as recommended by BS 6644. See Figure E1.1.1 for typical position.
E1.7 Circulating Pump
Each individual boiler is fitted with an integral circulating pump ensuring flow through the boiler and primary circuit. To
ensure the correct flow through the boiler, there is a balancing valve fitted to the flow pipe within the boiler. This is factory
set and must not be adjusted.
One or more circulating pumps will be required to circulate water around the heating system. All pumps should be
sited to facilitate servicing. It is important that when Fleet
boilers are used to replace boilers on an existing
system, the system design must be modified acknowledging the performance of the integral circulating pump.. It is
also important that the existing system be flushed through twice to remove any loose matter which may have
accumulated. To protect the boiler heat exchanger, it is strongly recommended that a dirt/air separator is fitted in
the return to the boiler. If in any doubt regarding the cleanliness of the system, a coarse filter should be fitted in
the return pipe work to the boilers.
E1.8 Minimum Water Flow Rates
Minimum water flow rates are shown in table at beginning of Appendix E. These flow rates should be maintained
through the boiler at all times whilst the boiler is firing. To prevent the boiler firing in the event of poor or no flow,
the boiler is fitted with an integral flow switch. Particular attention should be paid to the restriction of external flow
circuits during periods of low heat demand.
Each boiler module is fitted with a flow balancing valve on the return pipe within the unit. This valve may require
adjustment to ensure the correct flow through the boiler - refer to commissioning instructions Section 7.7
E1.9 Waterside Pressure Drop
The waterside hydraulic resistance (Pressure drop) is given in table at beginning of Appendix E.
E1.10 Water Flow Controls
The Fleet boiler is fitted with an integral circulating pump, which will shut off circulation 5 minutes after the boiler
has ceased firing.
Any external mixing valve / shunt pump or similar controls MUST always ensure that the minimum water flow rate
as given in table at beginning of Appendix E is maintained. As a precaution, the Fleet boiler is fitted with a flow
switch. The flow switch is designed to operate such that the boiler will shut down if insufficient flow occurs.
E1.11 Frost Protection
Consideration should be given to fitting an optional outside air sensor, to provide the necessary frost protection.
E1.12 Unvented Systems
Refer to Figure E1.1.1 on opposite page for typical layout of an unvented (Pressurised) Hot Water System. For
system design refer to BS 7074 Part 2. In order to correctly size a pressurisation unit for any heating system the
following parameters are required.
1) Static height of highest component in system (metres)
2) System volume. If this is not known, a general rule of thumb of 10litres/kW of installed boiler power
can be used.
3) Maximum flow temperature (°C)
4)
Maximum system hot working pressure, generally given in bar gauge.
From the parameters given, Hamworthy Heating can size the pressurisation unit and also the expansion vessel.
Care must be taken in sizing expansion vessels to ensure maximum acceptance factors are not exceeded.
Normally manufacturers of vessels impose a limit of 0.5. This value must not be exceeded at any time during the
operation of the boiler, this includes the over pressure condition should a safety valve lift.
Consideration should also be given to sizing of the safety valve(s) in the system. Refer to BS 6759: Part 1 for
further information and to BS 6880: Part 1 for design considerations.